Studies On The Synthesis, Characterization And Properties Of Polyaniline Doped With H₄SiW₁₂O₄₀

In the paper, dissoluble conducting polyaniline (PANI) is prepared by using the "in situ" polymerization method in the presence of polyvinyl alcohol (PVA), Microfibrous membranes of PVA contained PANI doped with H₄SiW₁₂O₄₀(PVA/PANI-H₄SiW₁₂O₄₀ are successfully prepared by an electrospinning technique. It is discovered that the PVA in the PVA/PANI-H₄SiW₁₂O₄₀ fibers will decompose when the fibers are irradiated with UV light. Meanwhile, PVA/PANI-H₄SiW₁₂O₍40 fibers mats contained TiO₂ are prepared by an electrospinning technique, PANI rods are obtained by catalysis degradation method under the UV light. PANI nanoslices are also getted by interfacial method. The main results are obtained as follows:1. PANI doped with H₄SiW₁₂O₄₀ is synthesized by using chemical oxidative polymerization of aniline in media containing PVA. This is a new polymerization method for the direct synthesis of the emeraldine salt of PANI that is soluble in water. The PANI is well characterizated by UV-Vis, IR spectra, and XRD pattern. The electrical conductivity of the PANI increases with decreasing amount of PVA in the experiment process. The highest conductivity of the PANI is 3.3 Son^-1, and the highest solubility of the PANI isl4.8 g/100g.2. PVA/PANI-H₄SiW₁₂O₄₀ microfibrous membranes are successfully prepared by an electrospinning technique. IR, UV-Vis spectra, XRD patterns and scanning electron microscopy (SEM) characterized the PAV/PANI-H₄SiW₁₂O₄₀ microfibrous membranes. The photochromic behavior of the PVA/PANI-H₄SiW₁₂O₄₀ microfibrous membranes is investigated by means of UV-Vis spectra. At the same time, the color of the PVA/PAN]-H₄SiW₁₂O₄₀ microfibrous membranes changed from green to blue under ultraviolet irradiation. A conceivable photochromic and polymeric mechanism is suggested.3. PVA/PANI-H₄SiW₁₂O₄₀ composite microfiber mats contained T1O2 are prepared by the electrospinning technique. The samples are characterized by SEM and IR techniques et al. The catalysis degradation process of the PVA/PANI-H₄SiW₁₂O₄₀ microfiber mats contained the TiO₂ as catalyzer under 254 run UV light irradiation is investigated. The results showed that the PVA in the PVA/PANI-H₄SiW₁₂O₄₀ microfiber mats has almost decomposed after UV light irradiation for 64 h, and the PANI nanorods are obtained in the end. Meanwhile, the possible photocatlytic degradation reaction mechanism of the PVA is suggested.4. PANI nanoslices is obtained by the interfacial polymerization method, H₄SiW₁₂O₄₀ is used as dopant, and ammonium peroxydisulfate is used as oxidant. The PANI nanoslices is characterizated by UV-vis, IR spectra, XRD pattern and SEM. The electronic conductivity of the PANI is also measured by four-probe method. The highest electronic conductivity of PANI nanoslices is 16.2 S/cm.